laminitis (lămˌənĪˈtĭs) [key], also called founder, inflammation of the lamina, the innermost layer of the hoof wall in horses, ponies, and donkeys. Although the condition usually affects only the front feet, it may involve all four feet. Both acute and chronic forms occur. The laminae become inflamed because of congestion of blood and accumulation of toxins in the hoof region resulting from any of several causes, e.g., consumption of large quantities of grain; ingestion of large amounts of cold water by overheated horses; concussion during fast, hard road work; and toxemia following pneumonia or infection of the uterus. The signs of acute laminitis appear rapidly and include sweating, a rise in temperature to as high as 106°F (62°C), a pounding pulse in the digital artery to the involved hoof, an expression of anxiety, and a stance with the legs forward of their natural position so as to reduce the pain of weight bearing. Chronic laminitis is characterized by a shifting or rotation of the bone and other anatomical distortions in the hoof. The disease is treated by eliminating the causative factors, administering drugs for the acute form, and trimming hooves and fitting corrective horseshoes for the chronic form.
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